Superconductivity

Superconductivity is a property that is found within certain materials, that allows them to suddenly exhibit zero resistance to the electric current and impermeability to external magnetic fields under certain circumstances. Although there are many different classifications of superconductors, they are usually classified as: either type I or type II, according to their ability to completely or imperfectly expel external magnetic fields; or as low or high temperature superconductors, depending on the critical temperature in which the material suddenly suffers the loss of electrical resistance and becomes a superconductor. Despite being discovered at the beginning of the 20th century, there is still a lot to be learned about this outstanding phenomenon that will bring relevant and promising applications related to energy.

Current investigation is focused on understanding the origin of the high-temperature superconductors and their properties. A high temperature superconductor is the one whose critical temperature is above the liquid helium temperature and generally below the liquid nitrogen one. For that reason, high-temperature superconductors can be refrigerated with liquid nitrogen, which is much cheaper and easier to handle than liquid helium. Andrea Cavallery’s team of researchers, from the Max Planck Institute for the Structure and Dynamics of Matter, were able to induce superconductivity at room temperature in a ceramic material by using short infrared laser pulses, but only lasting for a very short period of time. This experiment provided them with a better understanding of high-temperature superconductivity and encouraged them to continue investigating this research, applied to other kinds of materials. The use of high-intensity infrared light pulses has also been applied by scientists such as John Tranquada from U.S. Department of Energy’s Brookhaven National Laboratory, together with researchers from the Max Planck Institute and Oxford University, has allowed them to observe the transition to superconductivity above its expected critical temperature. This was witnessed in a material made up of lanthanum, barium, copper, and oxygen (LBCO). If these investigations continue to succeed in the future, they will be pushing towards wider applications of such superconducting materials.

Although some applications of superconductors are beginning to become reality, widespread use of the materials are still being researched in supranational projects and remain in a research and development stage. Superconductivity will radically affect the energy transmission industry, since it will allow the transmission of larger amounts of energy across long distances without resistive losses; in fact, there are those who imagine that a significant percentage of Europe’s power supply could come from the Sahara using a superconducting interconnection. Superconductivity will also have an impact on energy generation, by allowing the development of superconducting generators that, due to their lower size and weight, will ease their installation in off-shore wind turbines. It will also open the door to techniques such as plasma magnetic confinement, that will lead to nuclear fusion development as a clean and never ending energy.

Which application of superconductivity do you think that will have a greatest impact in the generation, transmission and use of energy? Which one will arrive earlier?